Allow broadcasting against lerp weights. (#52319)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52319
Fixes: https://github.com/pytorch/pytorch/issues/52254
Test Plan: Imported from OSS
Reviewed By: albanD
Differential Revision: D26488411
Pulled By: gchanan
fbshipit-source-id: 60eb471609986584c4235ba7f263581e988e7642
